1. Field
An air conditioner and a method for controlling an air conditioner are disclosed herein.
2. Background
In general, an air conditioner including a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger heats or cools an indoor space using a refrigeration cycle. That is, the air conditioner may include a cooler to cool the indoor space and a heater to heat the indoor space. In addition, the air conditioner may be used for both heating and cooling the indoor space.
When the air conditioner is configured for both heating and cooling, it may include a valve unit or valve that changes flowing paths of the refrigerant compressed at the compressor according to a cooling operation, a heating operation, and a defrosting operation. That is, the refrigerant compressed at the compressor may flow to the outdoor heat exchanger via the valve unit on or when performing the cooling operation wherein the outdoor heat exchanger acts as a condenser. Further, the refrigerant condensed at the outdoor heat exchanger may be expanded at the expansion valve, and then, may be introduced into the indoor heat exchanger. At this moment, the indoor heat exchanger may act as the evaporator, and the refrigerant evaporated at the indoor heat exchanger may be introduced again into the compressor via the valve unit.
Frost may be generated at or on the outdoor heat exchanger of the air conditioner, when an outdoor temperature is low, on or when performing the heating operation. Heating efficiency may be lowered when the frost is generated at the outdoor heat exchanger. Therefore, in order to remove the frost generated at the outdoor heat exchanger, the air conditioner may perform the defrosting operation to introduce the refrigerant, having a high temperature, compressed at the compressor into the outdoor heat exchanger.
In order to enhance efficiency of the air conditioner on or when performing the defrosting operation, it is required that refrigerant be injected into the compressor.